CN101607800B - Road lignin fiber and preparation method thereof - Google Patents

Abstract

The present invention relates to road lignin fiber and a preparation method thereof. The fiber comprises the following weight percentages of waste paper: 50-70% of waste publication paper and 30-50% of waste newsprint; the oil absorption rate of the waste publication paper should be 4-5 times, and the ash content should be 28-32%; the oil absorption rate of the waste newsprint should be 6-8 times, and the ash content should be 6-8%. The preparation method of the above fiber comprises: 1) preparing materials, respectively detecting and weighing the moisture and ash content of the raw materials; 2) chopping, and the chopping width is controlled at 10±3mm; 3) mixing, and the raw materials are put into a mixer for mixing; 4) crushing, and the screening rate when passing through a 0.15mm sieve hole is 70±10%. The present invention adopts a dry process, so that the entire production process has no chemical reaction, no wastewater discharge, and no impact on the surrounding environment. The process flow is simple and easy to control, the number of operators is small, and the energy saving can save a large amount of wood, water, electricity and chemical raw materials. The product quality and road performance have reached the quality standards of similar foreign products, reducing the production cost, and having obvious economic and social benefits.

Description

Road lignin fiber and preparation method thereof

technical field

The invention relates to a stabilizer in SMA asphalt mixture and a preparation method, in particular to a road-use lignin fiber and a preparation method.

Background technique

The full name of SMA is asphalt mastic macadam mixture. It is an asphalt mixture composed of asphalt fiber stabilizer, mineral powder and a small amount of fine aggregate. . Its structural strength comes from the interlocking and locking forces between the coarse aggregate skeletons. In terms of raw material composition, it has the characteristics of high content of coarse aggregate, mineral powder and asphalt and low content of fine aggregate; in terms of structure, it has the characteristics of effective embedding between aggregates, thick asphalt film, small void ratio and rough surface. The composition and structural characteristics of SMA determine that the mixture has excellent properties of anti-skid durability, compactness and durability, high temperature softening resistance and low temperature cracking reduction. In the production of asphalt mastic gravel mixture, an important material-fiber stabilizer must be used. Fiber is generally used, which is a necessary component of SMA. Researchers have developed many types of fibers, including lignin fibers, organic fibers, glass fibers and steel slag fibers. Road researchers added the above fibers to mastic macadam mixture (SMA) and did a lot of various performance tests. The test results show that the above-mentioned fibers have their own strengths and weaknesses in terms of performance. Comprehensively evaluating their overall performance and considering the economics of the project, lignin fiber is a more reasonable choice, so it has been widely used.

There are many different theories about the role of pavement lignin fibers in SMA mixtures, and it is difficult to confirm. From the perspective of road users, the mechanism is important, but the essence depends on the impact on asphalt mixtures. Used in SMA asphalt mixture, it mainly plays the role of stabilizer and enhancer.

With the continuous deepening of research, the irreplaceable role of fiber stabilizers in asphalt mixtures has gradually been recognized and affirmed by personnel, and some companies specializing in fiber production have also emerged at the historic moment, the more famous JRS company in Germany, American INTERFIBER company and FIBERAND company etc. The types of fibers have also developed from the initial mineral fibers and organic polymer fibers to the current mainstream lignin fibers.

In recent years, the SMA asphalt pavement paved with lignin fiber has received widespread attention due to its good performance and simple construction technology. Since Australia, Canada and other countries first added fiber materials to asphalt mixture in the 1960s, many countries in Europe and the United States have risen to a research climax of fiber-added asphalt pavement technology and have done a lot of work. The United States, Canada, Australia, Germany, Belgium, Austria and other countries have adopted fibers in many projects and formed some patented products, such as BoniFiber, GoodRoadII, FiberPave, Road-Celden in the United States, ARBOCELDolanitAS in Germany, etc.

my country's research on SMA started late, but since the first application of SMA technology to the construction of the "National First Road" Capital Airport Expressway in 1992, the research on SMA has developed rapidly in China. However, looking at the domestic research and development status, there is no substantive research on the systematic development of road-use lignin fiber products and production process control, and most manufacturers are still in the groping stage of imitating foreign production processes. , the variety of raw materials used is complex and the cost is high. Generally, wet process is used for production, which not only requires more equipment but also occupies a large area, and also requires a large area of slurry storage tank. The production investment is large, the manufacturing cost is high, and it is not easy to popularize and apply; During the production process, waste water is discharged, which is easy to pollute the surrounding environment, and consumes a lot of water and energy.

Contents of the invention

The purpose of the present invention is to provide a kind of road-use lignin fiber product and preparation method which requires single and low-cost raw materials, simple production process, low energy consumption, low production cost, no water consumption, and no environmental pollution. The above technical scheme is implemented:

The road-use lignin fiber includes waste paper in the following percentages by weight: 50-70% of waste paper, 30-50% of waste newsprint; the oil absorption rate of waste paper should be 4-5 times, and the ash content should be 20-30%. %; the oil absorption rate of waste newsprint should be 6-8 times, and the ash content should be 5-8%.

A dry process using the following steps:

1) Material preparation The moisture and ash content of waste newsprint and waste publication paper as raw materials are detected respectively, and should reach the specified range, and each raw material is weighed respectively according to the weight percentage;

2) Chopping: Shred the weighed raw materials with a shredder, and control the shredding width at 10 ± 3mm by controlling its rotating speed and feeding amount;

3) Mixing: put the chopped raw materials into the mixing machine according to the mass percentage ratio and mix them;

4) Pulverization The above-mentioned mixed material is sent into a pulverizer through a feeding device for pulverization, so that the sieving rate of the pulverized finished product material when passing through a 0.15mm sieve hole is 70 ± 10%;

5) After packaging and weighing, vacuum-seal the packaging with a PVE film-lined packaging bag, and the weighing error is not greater than 1%.

The pulverizer is an impeller-type super pulverizer. During the pulverization process, the particle size and fiber shape of the finished material are adjusted by controlling the amount of feed, the rotational speed of the impeller and the air volume of the system, so as to make it reach the above-mentioned screening rate.

The invention only uses two kinds of waste papers as raw materials to produce road-use lignin fiber products that meet quality standards, not only has a single variety of raw materials, but also turns waste into treasure and greatly reduces the cost of raw materials.

The invention adopts a dry process, so that there is no chemical reaction in the whole production process, no waste water discharge, no impact on the surrounding environment, simple process flow, fewer operators, easy control of process conditions, less equipment and easy operation, and consumes less energy. Less electricity and energy saving can save a lot of wood, water, electricity and chemical raw materials, so the production cost is greatly reduced, and it has obvious economic and social benefits.

The invention adopts general-purpose equipment, has low production investment cost, and is easy to start and prepare for construction. The quality and road performance of the road-use lignin fiber produced by the dry process have reached the quality standards of similar foreign products, and can completely replace imported products. It can be used for pavement construction, so that the localization of paving materials can be realized and the cost of paving can be reduced.

The invention uses the oil absorption rate and the ash content as the key indexes of raw material inspection, which makes the selection of raw materials convenient and quick and ensures the quality of road lignin fiber.

Description of drawings

Figure 1 is a graph showing the relationship between ash content and oil absorption.

Detailed ways

The inventors of the present application found that there is a fairly high correlation between the ash content of the fiber and the oil absorption rate through a large number of experimental studies. Please refer to FIG. 1 . As the ash content increases, the oil absorption rate decreases inversely. This is because: the oil absorption rate of inorganic minerals is inherently lower than that of natural fibers; at the same time, under the same weight, the higher the ash content, the lower the pure fiber content, and the effective ingredient to improve the oil absorption rate should be fiber rather than ash. A high ash content leads to a decrease in oil absorption. The selected raw material with high ash content will lead to low oil absorption index, so that it does not meet the specified requirements, and the road-use lignocellulose quality standard has clearly stipulated ash content requirements. Therefore, the present invention utilizes the characteristics of high oil absorption rate of waste newsprint and high ash content of waste publication paper, and obtains the suitable ratio of waste newsprint and waste publication paper on the basis of a large number of experiments, in order to achieve a product with both high oil absorption rate and high ash content. It meets the specified ash content requirements, thereby ensuring that the road-use lignin fiber of the present invention has good high and low temperature performance and meets the requirements of SMA road surface performance characteristics.

According to the correlation between the ash content and the oil absorption rate, the present invention proposes the oil absorption rate and the ash content index for waste paper raw materials as the reference index for preparing the raw material of road lignin fiber products, so as to control the raw material better, more conveniently and quickly, thereby ensuring product quality.

The present invention will be further described below with three embodiments.

Example 1

1) Prepare materials

The oil absorption rate and ash content of waste newsprint and waste publication paper raw materials are tested respectively, and the test indicators are as follows: and weighed according to the weight percentage;

                                                            

Waste journal paper 5.0 times 30%

Waste newsprint 6.0 times 5%

Weigh the above-mentioned raw materials according to the following mass percentage proportions:

Waste publication paper 70%;

Waste newsprint 30%

2) Chopped

Shred the weighed raw materials of waste newsprint and waste publication paper with a shredder, and control the shredding width at 10 ± 3mm by controlling its rotating speed and feeding amount;

3) Mixing

The shredded waste newsprint and waste magazine paper raw materials are weighed and put into a mixer at a weight ratio of 7:3 for thorough mixing.

4) Smash

The above-mentioned mixed materials are sent to the impeller super pulverizer through the feeding device for pulverization. During the pulverization process, the particle size and fiber shape of the finished material are adjusted by controlling the feed amount, impeller speed and system air volume, so that the pulverized finished material passes through 0.15 The sieving rate of mm sieve hole is 70±10%;

5) Packaging

The finished material is weighed according to the packaging weight, and the weighed finished material is poured into a packaging bag lined with PVE film through a special packaging machine, and vacuum-sealed for packaging, and the weighing error is not greater than 1%.

Example 2

1) Prepare materials

The oil absorption rate and ash content of waste journal paper and waste newsprint raw materials are tested respectively, and the test indicators are as follows: and weighed according to the weight percentage;

                                                 

Waste journal paper 4.5 times 25%

Waste newsprint 6.8 times 7%

Weigh the above-mentioned raw materials according to the following mass percentage proportions:

Waste publication paper 50%

Waste newsprint 50%;

2) Chopped

Shred the weighed raw materials of waste newsprint and waste publication paper with a shredder, and control the shredding width at 10 ± 3mm by controlling its rotating speed and feeding amount;

3) Mixing

The shredded waste newsprint and waste magazine paper raw materials are weighed and put into a mixer in a ratio of 1:1 by weight for thorough mixing.

4) Smash

The above-mentioned mixed materials are sent to the impeller super pulverizer through the feeding device for pulverization. During the pulverization process, the particle size and fiber shape of the finished material are adjusted by controlling the feed amount, impeller speed and system air volume, so that the pulverized finished material passes through 0.15 The sieving rate of mm sieve hole is 70±10%;

5) Packaging

The finished material is weighed according to the packaging weight, and the weighed finished material is poured into a packaging bag lined with PVE film through a special packaging machine, and vacuum-sealed for packaging, and the weighing error is not greater than 1%.

Example 3

1) Prepare materials

The oil absorption rate and ash content of waste newsprint and waste publication paper raw materials are tested respectively, and the test indicators are as follows: and weighed according to the weight percentage;

                                                    

Waste journal paper 4.0 times 20%

Waste newsprint 8.0 times 8%

Weigh the above-mentioned raw materials according to the following mass percentage proportions:

Waste publication paper 60%;

Waste newsprint 40%

2) Chopped

Shred the weighed raw materials of waste newsprint and waste publication paper with a shredder, and control the shredding width at 10 ± 3mm by controlling its rotating speed and feeding amount;

3) Mixing

The shredded waste newsprint and waste magazine paper raw materials are weighed and put into a mixer at a weight ratio of 3:2 for thorough mixing.

4) Smash

The above-mentioned mixed materials are sent to the impeller super pulverizer through the feeding device for pulverization. During the pulverization process, the particle size and fiber shape of the finished material are adjusted by controlling the feed amount, impeller speed and system air volume, so that the pulverized finished material passes through 0.15 The sieving rate of mm sieve hole is 70±10%;

5) Packaging

The finished material is weighed according to the packaging weight, and the weighed finished material is poured into a packaging bag lined with PVE film through a special packaging machine, and vacuum-sealed for packaging, and the weighing error is not greater than 1%.

Claims (3)

1. The lignin fiber for road is characterized in that it comprises the waste paper of following percentage by weight: 50～70% of waste publication paper, 30～50% of waste newsprint; the oil absorption rate of waste publication paper should be 4～5 times, and the ash content should be 20-30%; the oil absorption rate of waste newsprint should be 6-8 times, and the ash content should be 5-8%. 2. the preparation method of road-use lignin fiber as claimed in claim 1 is characterized in that adopting the dry process of following steps: 1) Material preparation The moisture and ash content of the waste newsprint and waste publication paper used as raw materials are tested respectively, and should reach the above-mentioned specified range, and each raw material is weighed according to the weight percentage; 2) Chopping The weighed raw materials are shredded with a shredder, and the shredding width is controlled at 10 ± 3mm by controlling its rotating speed and feeding amount; 3) Mixing: Put the chopped raw materials into the mixer with the mass percentage ratio and mix them; 4) Pulverization The above-mentioned mixed material is sent into a pulverizer through a feeding device for pulverization, so that the sieving rate of the pulverized finished product material when passing through a 0.15mm sieve hole is 70 ± 10%; 5) After packaging and weighing, vacuum-seal packaging with a packaging bag lined with PVE film, and the weighing error is not greater than 1%. 3. the preparation method of road-use lignin fiber according to claim 2, is characterized in that described pulverizer is impeller type super pulverizer, by controlling feed rate, impeller rotating speed and system air volume size in pulverizing process, regulates Finished material particle size and fiber morphology to achieve the stated sieve ratio.

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